<template>
  <div class="todo-footer" v-show="total">
        <label>
        <!-- <input type="checkbox" :checked="isAll" @change="checkAll"/> -->
         <!-- 使用下面这种方式更简单 -->
        <input type="checkbox" v-model="isAll"/>
       
        </label>
        <span>
        <span>已完成{{ doneTotal }}</span> / 全部{{ total }}
        </span>
        <button class="btn btn-danger" @click="clearAll">清除已完成任务</button>
    </div>
</template>

<script>
    export default {
        name:'MyFooter',
        // props:['todos','checkAllTodo','clearAllTodo'],
        props:['todos'],
        computed:{
            total(){
                return this.todos.length
            },
            doneTotal(){
                return this.todos.reduce((pre,cur)=>{
                    return pre + (cur.done ? 1: 0)
                },0)
            },
            isAll:{
                get(){
                    return this.doneTotal === this.total && this.total > 0
                },
                set(value){
                    // this.checkAllTodo(value)
                    this.$emit('checkAllTodo',value)
                }
            }
        },
        methods:{
            checkAll(e){
                // this.checkAllTodo(e.target.checked)
                this.$emit('checkAllTodo',e.target.checked)
            },
            clearAll(){
                // this.clearAllTodo()
                this.$emit('clearAllTodo')
            }
        }

    }
</script>
<style scoped>
     /*footer*/
     .todo-footer {
    height: 40px;
    line-height: 40px;
    padding-left: 6px;
    margin-top: 5px;
    }

    .todo-footer label {
    display: inline-block;
    margin-right: 20px;
    cursor: pointer;
    }

    .todo-footer label input {
    position: relative;
    top: -1px;
    vertical-align: middle;
    margin-right: 5px;
    }

    .todo-footer button {
    float: right;
    margin-top: 5px;
    }
</style>